builder-web/lib/dream_tar.ml

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open Lwt.Infix
module Writer = struct
type out_channel = Dream.stream
type 'a t = 'a Lwt.t
let really_write stream cs =
Dream.write stream (Cstruct.to_string cs)
end
module HW = Tar.HeaderWriter(Lwt)(Writer)
let write_block (header : Tar.Header.t) lpath stream =
HW.write ~level:Tar.Header.Ustar header stream >>= fun () ->
Lwt_io.open_file ~mode:Lwt_io.Input (Fpath.to_string lpath) >>= fun ic ->
let buf_len = 4 * 1024 * 1024 in
let buf = Bytes.create buf_len in
let rec loop () =
Lwt_io.read_into ic buf 0 buf_len >>= fun r ->
if r = 0 then
Lwt.return_unit
else
Dream.write stream (Bytes.sub_string buf 0 r) >>= fun () ->
loop ()
in
loop () >>= fun () ->
Dream.write stream (Cstruct.to_string (Tar.Header.zero_padding header))
let header_of_file mod_time (file : Builder_db.file) =
let file_mode = if Fpath.is_prefix Fpath.(v "bin/") file.filepath then
0o755
else
0o644
in
Tar.Header.make ~file_mode ~mod_time (Fpath.to_string file.filepath) (Int64.of_int file.size)
let tar_response datadir finish (files : Builder_db.file list) (stream : Dream.stream) =
Lwt_list.iter_s (fun file ->
let hdr = header_of_file finish file in
write_block hdr Fpath.(datadir // file.localpath) stream)
files >>= fun () ->
Writer.really_write stream Tar.Header.zero_block >>= fun () ->
Writer.really_write stream Tar.Header.zero_block >>= fun () ->
Dream.flush stream >>= fun () ->
Dream.close stream